The writer needed an extraordinarily low cost and simple alarm for some of hellos possessions, one of theses hellos electrically assisted bicycle. This alarm is in accordance with a low-cost window alarm, which has a time-switch delivered to it with a 1-minute time-out. The output pulse of the 555 substitutes the reed change in the window alarm. The 555 is brought about through a sensor mounted near the entrance wheel, in combination with a magnet that's mounted on the spokes. This sensor and the magnet have been taken from an affordable bicycle laptop.
Circuit diagram :
Cheap Bicycle Alarm Circuit Diagram
The entrance wheel of the bicycle is stored unlocked, so that the reed change closes momentarily when the wheel flips. This set offs the 555, which in turn prompts the window alarm. The circuit around the 555 takes very little present and can be powered by means of the batteries in the window alarm. There is just sufficient room left inside the enclosure of the window alarm to mount the time-switch inside of it.
The result is a very low-cost, compact device, with handiest a single cable going to the reed swap on the front wheel. And the noise this factor produces is solely unbelievable! After about one minute the noise stops and the alarm goes again into standby mode. The bicycle alarm should be established in an not noticeable place, this type ofs underneath the saddle, inside of a (large) entrance light, in the battery compartment, etc.
Hopefully the alarm scares any attainable thief away, or at least it makes other individuals of the common public aware that one thing isnt moderately proper.
Caution. The installation and use of this circuit could also be subject to prison restrictions for your country, state or area.
Author : Gerard Seuren
